4. LA in Children Flashcards
Functions of LA (3)
Operative pain control
Haemorrhage control
Diagnostic tool
Definition of surface anaesthesia
Anaesthesia of surface tissues (skin/mucous membranes)
Functions of surface anaesthesia (3)
Reduce pain of LA injection
Reduce discomfort of venepuncture
For superficial soft tissue manipulation
Methods of achieving surface anaesthesia (2)
Physical - refrigeration anaesthesia
Pharmacological - topical anaesthesia
Features of refrigeration anaesthesia (6)
Achieved by reducing temperature
Ethyl chloride (rarely used as LA agent in children)
Difficult to direct stream of liquid accurately
Inadvertent contact with vital teeth produces discomfort
Inflammable
Excessive use can render the patient unconscious
Types of pharmacological anaesthesia (4)
Intra-oral topical agents
Topical anaesthesics for skin
Controlled release devices
Jet injectors
Action of intra-oral topical agents
Anaesthetise 2-3mm depth of tissues
Uses of intra-oral topical LA (7)
Pre-injeciton Rubber dam clamp Placing matrix band Suture removal Exfoliating primary teeth Subgingival scaling Incision of abscess
Types of topical anaesthetic for skin (2)
EMLA cream
Ametop gel
Types of topical release devices
Patches
Advantages of topical jet injectors (4)
Allows anaesthesia up to 10mm
Used when bleeding diatheses/when deep injections are contra-indicated
Sole means of achieving LA
Prior to conventional techniques
Disadvantages of topical jet injectors (4)
Could cause soft tissue damage if used carelessly
Frightening sight and sound
Taste of solution
Expensive
Types of non-pharmacological pain control (2)
TENS (transcutaneous electrical nerve stimulation - GCT pain theory. Used for restorations, primary extractions, pre-LA)
Hypnosis (altered state of mind such that suggestions are accepted more readily and acted upon more powerfully. Adjunct to LA)
Features of lidocaine (3)
Anti-arrhyhtmic drug
Rapid onset of action
Suitable for infiltration, block and surface anaesthesia
Lidocaine contraindications (4)
Heart block, no pacemaker
allergy to LA/corn
Hypotension
Impaired liver function
Features of articaine (2)
Risk of systemic toxicity is lower than others - hydrolysed in blood quicker
Thiophene ring instead of benzene, additional ester group
Articaine contraindications (2)
Avoid in sickle cell patients
Avoid with haemoglobinopathies
Adrenaline effect (4)
Binds to a1 receptors causing vasoconstriction
Binds to b1 receptors causing tachycardia
Could increase HR
Could increase BP (HR increase and peripheral constriction)
LA techniques in children (3)
Infiltration
Intraligamentray
Regional block
Uses of LA infiltration (5)
Anaesthesia in primary teeth
Anaesthesia in maxillary permanent teeth
Anaesthesia in mandibular permanent anterior teeth
Prior to intrapapillary and then intraligamental anaesthesia in posterior permanent teeth
Prior to intrapapillary and palatal/lingual anaesthesia
Uses of LA intraligamentary (2)
Supplement infiltrations
Eliminate need for block
Intraligamentary LA can be tender due to pressure. Method to reduce discomfort (3)
Small buccal infiltration
Papillary injection
Intraligamental injection
Features of the LA Wand (4)
Method of intraligamentary LA
Uses computerised flow of LA
Can be used as a method of intraligamental LA for single tooth anaesthesia
Can also be used for infiltration and block anaesthesia
Mandibular foramen difference between adults and kids (2)
Adults - higher
Kids - lower, often below occlusal plane
Advantage of mental block
Very good soft tissue anaesthesia
Disadvantages of mental block (2)
Incisive nerve anaesthesia not as reliable as IDB
Incisors may get crossover supply across midline, so need a labial infiltration adjacent to tooth as well as this block
LA allergy features (3)
Very rare, especially to amide group
Metabisulphite (E223) preservative, antiseptic
Methyl parabens preservative (E218) found in blueberries
LA toxicity features (4)
Cardiovascular (low levels – stimulant; high levels – circulatory collapse)
CNS (depressant leading to unconsciousness and respiratory arrest)
Methaemoglobinaemia (cyanosis associated with lethargy and respiratory distress)
Prilocaine, Articaine, benzocaine (reduced ability of red blood cells to release oxygen to tissues)
Treatment of LA toxicity (5)
Stop dental treatment Provide basic life support Call for medical assistance Protect patient from injury Monitor vital signs
Early localised LA complications (5)
Pain Intravascular injection LA failure Motor nerve paralysis Haematoma formation
Late localised LA complications (6)
Self-inflicted trauma Oral ulceration Long-lasting anaesthesia Trismus Infection Developmental defects
LA contraindications (4)
Bleeding disorders (avoid IDB)
Allergy
Acute infection
Liver disease (reduce amide dose)
Techniques for LA in children (7)
Positive reinforcement Tell/show/do Acclimatisation Desensitisation Voice control Distraction Role modelling
